Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['3401', 'M', 'Z', 'r', '8619', 'J']

3401, 13, 26, 18, 8619, 10